Hello,

I bought a mk1 Focus RS today.

It has a boost problem. It appears to be laggy and when it does boost it peaks at 15psi and then the boost drops back off around 5000rpm until it is back to 0psi.

Mods are:

Bluefin
Tubular Manifold
Full Exhaust
K&N Filter

It has had a recent turbo and actuator.

Any suggestions or common problems?

I am going to check for obvious things that could cause a boost leak etc.

Thanks,
Stephen

 

Has the turbo intake pipe been changed or is it the standard jobby as the originals get soft and collapse.
Also you could try running the car direct and bypass the Amal valve to see if that's faulty but be very careful when doing this.
Failing that check all boost pipes.
Could also be a faulty dump valve if it's the standard one, you could blank it off to make sure it's not that.
I had the same issues your deceiving and mine turned out to be the vacuum hose to the dump valve was kinked and the boost pressure at that rpm was opening the dump valve early.

 

Noticed your in Scotland the car didn't happen to be taken to a well known tuner in Dunfermline did it as mine went to the same place and came out just as bad but the took £350 off me and said we would change the turbo. Mine only had 40k miles and was standard.

 

Ahh good old Shitec racing? Been there done that and won't do it again.

OP my mate owned a mk1 rs and his has boost problems, got it smoke tested and turned out to be a hose burst, iirc it was a short black hose under the inlet manifold and was about 15mm inside dia. That was burst quite bad then his blue charge hoses went after he got that sorted.

 

We got one of those smoke testers at work there awesome

 

Good mate aren't they save a lot of time especially in a tight engine bay where you can't see jack shit lol.

 

Thanks for all the suggestions. It had an air leak on a vaccum pipe so was an easy sort.

I wouldnt let sitech work on my lawnmower let alone a car. 😂